Air distributing valves



July 12, 1960 Filed July 24, 1959 FIG.

2 Sheets-Sheet 1 I I9 43 29 lOl I43 I 55 I37 145 x 23 49 1 Z 4 4 I03 871 3 4a 97 3 y 1960 D. e. PHINNEY 2,944,528

AIR DISTRIBUTING VALVES Filed July 24. 1959 2 Sheets-Sheet 2 UnitedStates. Patent F 10 Claims. 01. 121-465) This invention relates todistributing valves,iand l more particularly to anti-icing means for thedistribut -v 1 ing valve of anexpansible-chamber air -motor.

The invention involves an improvement upon the'air distributing valve ofan air motor of the type such as shown in Klein United States Patent2,750,932: com- 2 heads. This block has a flat outer face 17, feed passages-19 and 21 and an exhaust passage 23. Thelatter is formed by a hole25 extending transversely'complete- 1y across the block locatedcentrally of the length of the block and ,by'an entrance hole 27 boredin from the outer face 17 of the block to an intersectionwith holeprising a cylinder, a piston working in the cylinder, and valve meansincluding a slidable main distributing valve member having a cavitytherein for controlling the 7 supply of air to and the exhaust of airfrom the opposite ends of the cylinder. A problem which has been en 25countered in the operation of such. air motors, particu-' larly asregards larger capacity motors, is the formation" of ice in the cavityof the slidable main distributing valve-- member which may at times beserious enough to' block flow through the cavity. Ice may form,particularly; when the air is humid, because of thefcooling effect ofthe expansion of air in the cavity. Accordingly, among the severalobjects of this invention may be noted the provision of means foretfective i ly preventing the accumulation of' ice in the cavity of theslidable main distributing valve member; and the provision of suchanti-icing means which does not interfere with the action of the valvemember, and which 'is economical to manufacture and install. Otherobjects 4 and features will be in part apparent and in part pointed outhereinafter.

The invention accordingly comprises the constructions hereinafterdescribed, the scope of the invention being indicated in the followingclaims. In the accompanying drawings, in which one of various possibleembodiments of the invention is illustrated,

Fig. 1 is a longitudinal section of an air motor hav-. ing adistributing valve provided with anti-icing means of this invention; IFig. 2 is an enlarged fragment of Fig. 1 with parts further broken awayand shown in section;

Figs. 3 and 4 are enlarged transverse sections taken on lines 3-3 and44, respectively, of Fig. 1;

Fig. is a longitudinal section taken on line 55 of Fig. 3; and, a

25. The feed passage 19 is formed by a longitudinal hole 29 boredin fromthe upper. end of the block to a point short of the hole and by a hole31 bored in from the face 17 of the block to an intersection with. thelower end of hole 29. The feed passage 21 is formed by alongitudinalhole 33 bored in from the lower end" of the block to a point shortof thehole 25 and by. a

hole 35 bored in from the face 17 of the block to an intersection withthe upper end of hole 33. Holes '29 and 33 open into passages 37 and 39in the upper and lowed end heads 7' and 9, respectively.'

Avalve seat face plate 41 is securedon face 17 of block 15. A valvechest 43 is secured to block 15 over This chest has upperand lowerlongitudinal this plate.

cylindrical bores 45 and 47 open to an enlarged central 0 main D-val=vemember 87.

45 members.

pressure "chamber 49. Compressed air for driving the motor is deliveredto chamber 49 through an air inlet 51. A valve-actuating piston isadapted for length wise reciprocation in the valve chest 43, the ends ofthe piston being slidable in the bores 45 and 47. Valve gear foroperating the piston 55 from the motor piston. 11 is indicated at 71.This is essentially the same asthat; shown in "the aforesaid UnitedStates Patent 2,750,--

. 932 andreference may be made thereto for full details. As in the motorshown in United States; Patent 2,750,932 piston 55 controls a maindistributing slide valve member 87 and an auxiliary distributing slidevalve member 89. The main valve member 87 is a D-valve .slidable onvalve seat plate 41. It controls the supply I and exhaust of air to andfrom the opposite ends of motor cylinder 3. Theauxili-ary valve member89 is. also a D-valve slidable on valve seat plate 41 at one side of Itcontrols the supply and exhaust of air to and from. the outer ends ofbores 45 and 47 in valve chest 43. On valve seat plate 41 issecuredaplate 90 having an opening 91 therein which serves as a guideand end stop for the two slide valve The main D-valve member 87, asshown, is relatively short and wide as compared to the auxiliary D-valvemember 89, the latter being relatively long'and narrow. The opening 91is shaped somewhat like a T, as shown in United States Patent 2,750,932,having a relatively short wide portion accommodating the sliding of themain D-valve member 87 and a longer narrow Fig. 6 is a perspective of areed which is incorporated i the upper end of a piston rod 13 whichextends through the lower head. Avalve seat block 15 extends; lengthwiseon the outside ofthe cylinder betweenthe end portion accommodating thesliding of the auxiliaryv D- valve member 89. The two D-valve membersare guided by the'sides of the opening 91. The piston 55 has anotch 97corresponding in length to the length of the auxiliary D-valve member89. This notch receives the shorter main D-valve member 87 withlost-motion (see Fig. 1)." Engagement of the ends of the auxiliaryD-valve mem-' ber 89 with the ends of opening 91 determines the limitingend positions of the piston 55.-

In the line of motion of the main D-valve member 87, r the valve seatplate 41 has a mainv central exhaust port 99 aligned with the hole 27 ofexhaust passage 23 in 5 the block 15, a main feed port 101 above port 99aligned with the hole 31 of feed passage19 and a main feed port 103below port 99 aligned with the hole 35 of feed passage 21. The portingarrangement for the supply and exhaust of air'to and from the outer endsof bores 45 L and 47-under control of the auxiliary D-valve member 59 isessentially the same as that shown in United Statesimitated July 12, 190- Patent 2,750,932. Referencemay be made to said'patent for fulldetails.

In accordance with this invention, the cavity 129 in the main D-valvemember 87 is of arcuate form lengthwiseof-the valve member, concave asregards the inside face ofthe valve member. 129 is preferably coated asindicated at C'with a material which tends to prevent ice from adheringthereto, such as a silicone resin, or polymerized tetrafiuoroethylene(sold This provides a relatively thin annular rim 135 at the other endof the hole- A plug 137 made of elastomeric material, preferably asynthetic rubber such as that sold under the trade name neoprene, issecured to the block 15 under compression in the hole 131. For thispurpose, the plug has 'a circular base portion 139 provided with anannular groove 141 which receives the rim 135. The plug also has anintegral stem portion 143 extending from the base portion 139 into thetransverse exhaust hole 25 in the block toward and in line with theexhaust hole 27 in the block and the 'main central exhaust port. 99 inthe valve plate 41. The stem portion 143 is molded around a flat reed145, which may be made of Phosphor bronze spring strip material havingawidth somewhat less than the width of the cavity 129 in the main D-valve87. The reed 1 15 is shown as having a hole 147 therein which is filledwith rubber during the molding of the plug to hold the reed in assemblywith the plug. The reed is of such length as to extend through the hole27 and port 99 and beyond valve plate 41 into the cavity 129 in the mainD- valve 87. The plug 137 is turned so that the plane of the reed istransverse to the length of the main D-valver The reed normally isperpendicular to the plate 41, and,

when perpendicular, projects beyond the face of the plate I 41 a.distance approximately half the maximum depth of the cavity 129 in themain D-valve (see Figs. 1 and 2). Notches such as indicated at 149 inFig. 6 are provided at the lower end of the plug for receiving keys suchas indicated at 150 at opposite sides of hole 133 to hold the assemblyof the plug and reed from rotating out of proper position. a

It will be understood that the main D-valve member 87 'is' slidable backand forth on valve seat plate 41 between a first position wherein thecavity 129 in the D- valve member 87 provides for communication from afirst feed port (port 103 as shown in Figs. 1 and 2) to the exhaust port99 and a second position wherein the cavity provides for communicationfrom the second feed port (101) to the exhaust 99. In the first positionof D-valve member 87, air is supplied from the chamber 49 to the upperend of the cylinder 3 via feed port 101 and feed passages 19 and 37, andexhausted from the lower end of the cylinder via feed passages 39 and21, port 183 and cavity 129. member 87, air is supplied from the chamber49 to the lower end of the cylinder 3 via feed port 183, and exhaustedfrom the upper end of the cylinder via passages 37 and 19, port 101 andcavity 129.

Expansion of air in cavity 129 tends to cause. cooling of the air andfreezing of moisture in the air in the cavity, but reed 145, which isoscillable in the exhaust port 99 in the line of movement of the D-valvemember 87,

prevents accumulation of ice in the cavit aided by thecoating C. Reed145 also prevents icing in port 99 and holes 27 and -25, asmay occurwithout the reed. The exact manner in which the reed prevents theaccumula- The surface of the cavity In the second position of theD-valve tion of ice is not precisely understood at'present, but it actsmost effectively for this purpose, without interfering with the flow ofair. The tendency toward icing in the cavity of the, auxiliary D-valve89 is much less than the tendency toward icing in the cavity of the mainD-valve 87. Hence, it is not necessary to provide a reed for theauxiliary D-valve.

In view of the above, it will be seen that the several 1 objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the 7 above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim: v

1. In an air distributing valve comprising a valve seat having anexhaust port between first and second feed ports, and a valve memberhaving a cavity therein slidable back and forth between a first positionwherein the cavity provides for communication from the first feed portto the exhaust port and a second position wherein the cavity providesfor communication from the second feed port to the exhaust port,expansion of air in said cavity tending to cause cooling of the air andfreezing of moisture in the air in the cavity; means for-preventing 2.In an air distributing valve as set forth in claim a 1, said cavitybeing of arcuate form lengthwise of said slidable member and having acoating of material resistant to adherence of ice. v

3. In an air distributing valve as set forth in claim -2, said reedprojecting into said arcuate cavity a distance less than the maximumdepth of said arcuate cavity.

4. In an air distributing valve as set forth in claim 1, said reedcomprising a length of spring strip material.

5. In an air distributing valve as set forth in claim 4, said reedhaving an end portion embedded in a base of elastomeric material, saidbase being secured in a hole in said valve seat.

6. In an air distributing valve for an air motor, said motor comprisinga cylinder and a piston movable in the cylinder, said valve comprising ablock extending lengthwise of the cylinder on the outside thereof, aplate on the outer face of the black constituting a valve seat, a valvechest overlying said plate, said block having an exhaust passageincluding a transverse hole and an entrance hole extending from theouter face of the block to said transverse hole, said block also havingfeed passages in communication with the ends of the cylinder, said platehaving an exhaust port in communication with said entrance hole in theblock and first and second feed ports on opposite sides of the exhaustport in communication with the feed passages in the block, a D-valvemember having a cavity therein slidable back and forth on said platebetween a first position wherein the cavity provides for communicationfrom the first feed port to the exhaust port and a second positionwherein the cavity provides for com munication from the second feed portto the exhaust port, expansion of air in the cavity tending to causecooling of the air and freezing of moisture in the air therein; means,for preventing accumulation of ice in the cavity comprising a reedattached to the block extending through said cavity being of arcuateform lengthwise of said D-valve member and having a coating of materialresistsaid reed having an end portion embedded in a base of ant toadherence of ice. elastomeric material, said base being secured in ahole 8. In an air distributing valve as set forth in claim 7, in thebottom of the block.

said reed projecting into said arcuate cavity a distance less than themaximum depth of said arcuate cavity. 5 References Cited in the file ofthis patent 9. In an air distributing valve as set forth in claim 6,

said reed comprising a length of spring strip material. UNITED STATESPATENTS 10. In an air distributing valve as set forth in claim 9,2,750,932 Klein June 19, 1956 Q

